Wei Jiahua

Spatial integrated analysis on water erosion of Yellow River China

Using remote sensing technology applied to research water erosion introduced firstly, and then choosing such data mining approaches as spatial statistical analysis and spatial cluster analysis to discuss the relationship between water erosion and geologic environment and other factors of Yellow River. The results show in two aspects below. (1) The character of spatial distribution was compared under the condition of different grade elevation, average temperature per year, rainfall and other geographic environment factors. The percentage of water erosion area above heavy under the condition of six-grade elevation (elevation between 1501 and 20000), eight-grade average temperature per year (between 8.1 and 10 centigrade) and five-grade rainfall (between 400.1 and 500 mm) is more than any other geographic environment. (2) On the basis of geographic environment factors, the discrepancy of the region of water erosion of Yellow River was analyzed using spatial cluster analysis, and the water erosion percentage of the fifth type account for most of all these ten regions.

Sky River: Discovery, concept, and implicationsfor future research

Presented in this paper is a brief introduction to our recent discovery and definition of Sky River, as well as its implications for future research. Based on meteorological reanalysis data, we found that there exist highly structured water vapor conveyance systems in the troposphere of the atmosphere. The water vapor conveyance systems have higher vertically integrated flux than their immediate environments, consisting the dominant channels from local scale to global scale for atmospheric water vapor transfer. The water vapor transfer systems in the troposphere share the similarity of having high water (vapor) conveyance with land surface rivers and thus can be referred to as “River in the Sky”, or simply “Sky River”. Sky River is different from “atmospheric river” essentially in that it is a global system where water vapor concentrated and conveyed by atmospheric circulations, rather than the transient and local high flux belts found in previous studies. Studies on the Sky Rivers will help us to have a new vision about global atmospheric water vapor transfer and a better understanding of global water cycle.

Study on the Evaluation Method of Groundwater Vulnerability to Pollution from Informal Landfills in Regional Scale

Aimed at the increasing severe domestic wastes pollution, evaluation model of groundwater vulnerability to pollution from informal landfills in regional scale has been proposed. It is based on the DRASTIC model and LeGrand model, considering the characteristics of regional geology and hydrogeology, as well as pollution that landfills do to groundwater. Then the actual and potential risks in groundwater environment that are caused by informal landfills have been quantified. Take the Beijing Plain as example, which shows the method is feasible and the result is reliable.

Adaptive control model of water resources regulation in the Yellow River

According to the principle of procedure control and the characteristic of stochastic of inflow and water demands, this paper deals with the application of adaptive control to a water resources regulation system. The main control objective is to approach the vested target of water resources allocation by controlling the reservoir discharge and water demand. The adaptive control implemented is based on the linear quadratic control approach. Models of water balance, reservoir adjusted model and allocation model are used for the control purposes. The results show the performance of this adaptive scheme and its ability to control the water resources allocation process.